ref: 1bc7f0b665afa19c97314f8e4606407d4ead470f
dir: /shaders.inc/
Point3
gouraudvshader(Shaderparams *sp)
{
static double Ka = 0.1; /* ambient factor */
static double Ks = 0.5; /* specular factor */
double Kd; /* diffuse factor */
double spec;
Point3 pos, lightdir, lookdir;
Material m;
LightSource *l;
Color ambient, diffuse, specular, lightc;
sp->v->n = model2world(sp->su->entity, sp->v->n);
sp->v->p = model2world(sp->su->entity, sp->v->p);
pos = sp->v->p;
if(sp->v->mtl != nil)
m = *sp->v->mtl;
else{
memset(&m, 0, sizeof m);
m.diffuse = sp->v->c;
m.specular = Pt3(1,1,1,1);
m.shininess = 1;
}
lightc = getscenecolor(sp->su->camera->scene, pos, sp->v->n);
sp->v->c = Vec3(0,0,0);
for(l = sp->su->camera->scene->lights.next; l != &sp->su->camera->scene->lights; l = l->next){
lightdir = normvec3(subpt3(l->p, pos));
ambient = mulpt3(lightc, Ka);
ambient = modulapt3(ambient, m.diffuse);
Kd = max(0, dotvec3(sp->v->n, lightdir));
diffuse = mulpt3(lightc, Kd);
diffuse = modulapt3(diffuse, m.diffuse);
lookdir = normvec3(subpt3(sp->su->camera->p, pos));
lightdir = qrotate(lightdir, sp->v->n, PI); /* reflect */
spec = pow(max(0, dotvec3(lookdir, lightdir)), m.shininess);
specular = mulpt3(lightc, spec*Ks);
specular = modulapt3(specular, m.specular);
sp->v->c = addpt3(sp->v->c, addpt3(ambient, addpt3(diffuse, specular)));
}
sp->v->c.a = m.diffuse.a;
return world2clip(sp->su->camera, pos);
}
Color
gouraudshader(Shaderparams *sp)
{
Color tc;
if(sp->v->mtl != nil && sp->v->mtl->diffusemap != nil && sp->v->uv.w != 0)
tc = sampletexture(sp->v->mtl->diffusemap, sp->v->uv, tsampler);
else
tc = Pt3(1,1,1,1);
sp->v->n.w = 1;
sp->toraster(sp, "normals", &sp->v->n);
return modulapt3(sp->v->c, tc);
}
Point3
phongvshader(Shaderparams *sp)
{
Point3 pos;
Color a, d, s;
double ss;
sp->v->n = model2world(sp->su->entity, sp->v->n);
sp->v->p = model2world(sp->su->entity, sp->v->p);
pos = sp->v->p;
sp->setattr(sp, "pos", VAPoint, &pos);
if(sp->v->mtl != nil && sp->v->mtl->normalmap != nil && sp->v->uv.w != 0){
sp->v->tangent = model2world(sp->su->entity, sp->v->tangent);
sp->setattr(sp, "tangent", VAPoint, &sp->v->tangent);
}
if(sp->v->mtl != nil){
a = sp->v->mtl->ambient;
d = sp->v->mtl->diffuse;
s = sp->v->mtl->specular;
ss = sp->v->mtl->shininess;
sp->setattr(sp, "ambient", VAPoint, &a);
sp->setattr(sp, "diffuse", VAPoint, &d);
sp->setattr(sp, "specular", VAPoint, &s);
sp->setattr(sp, "shininess", VANumber, &ss);
}
return world2clip(sp->su->camera, pos);
}
Color
phongshader(Shaderparams *sp)
{
static double Ka = 0.1; /* ambient factor */
static double Ks = 0.5; /* specular factor */
double Kd; /* diffuse factor */
double spec;
Color ambient, diffuse, specular, lightc, c;
Point3 pos, n, lightdir, lookdir;
Material m;
LightSource *l;
RFrame3 TBN;
Vertexattr *va;
va = sp->getattr(sp, "pos");
pos = va->p;
va = sp->getattr(sp, "ambient");
m.ambient = va != nil? va->p: Pt3(1,1,1,1);
va = sp->getattr(sp, "diffuse");
m.diffuse = va != nil? va->p: sp->v->c;
va = sp->getattr(sp, "specular");
m.specular = va != nil? va->p: Pt3(1,1,1,1);
va = sp->getattr(sp, "shininess");
m.shininess = va != nil? va->n: 1;
/* normal mapping */
va = sp->getattr(sp, "tangent");
if(va == nil)
n = sp->v->n;
else{
/* TODO implement this on the VS instead and apply Gram-Schmidt here */
n = sampletexture(sp->v->mtl->normalmap, sp->v->uv, neartexsampler);
n = normvec3(subpt3(mulpt3(n, 2), Vec3(1,1,1)));
TBN.p = Pt3(0,0,0,1);
TBN.bx = va->p; /* T */
TBN.bz = sp->v->n; /* N */
TBN.by = crossvec3(TBN.bz, TBN.bx); /* B */
n = normvec3(invrframexform3(n, TBN));
}
if(sp->v->mtl != nil && sp->v->mtl->diffusemap != nil && sp->v->uv.w != 0)
m.diffuse = sampletexture(sp->v->mtl->diffusemap, sp->v->uv, tsampler);
if(sp->v->mtl != nil && sp->v->mtl->specularmap != nil && sp->v->uv.w != 0)
m.specular = sampletexture(sp->v->mtl->specularmap, sp->v->uv, tsampler);
lightc = getscenecolor(sp->su->camera->scene, pos, n);
c = Vec3(0,0,0);
for(l = sp->su->camera->scene->lights.next; l != &sp->su->camera->scene->lights; l = l->next){
lightdir = normvec3(subpt3(l->p, pos));
ambient = mulpt3(lightc, Ka);
ambient = modulapt3(ambient, m.diffuse);
Kd = max(0, dotvec3(n, lightdir));
diffuse = mulpt3(lightc, Kd);
diffuse = modulapt3(diffuse, m.diffuse);
lookdir = normvec3(subpt3(sp->su->camera->p, pos));
lightdir = qrotate(lightdir, n, PI); /* reflect */
spec = pow(max(0, dotvec3(lookdir, lightdir)), m.shininess);
specular = mulpt3(lightc, spec*Ks);
specular = modulapt3(specular, m.specular);
c = addpt3(c, addpt3(ambient, addpt3(diffuse, specular)));
}
c.a = m.diffuse.a;
n.w = 1;
sp->toraster(sp, "normals", &n);
specular.a = 1;
sp->toraster(sp, "specular", &specular);
return c;
}
Color
blinnshader(Shaderparams *sp)
{
static double Ka = 0.1; /* ambient factor */
static double Ks = 0.5; /* specular factor */
double Kd; /* diffuse factor */
double spec;
Color ambient, diffuse, specular, lightc, c;
Point3 pos, n, lightdir, lookdir;
Material m;
LightSource *l;
RFrame3 TBN;
Vertexattr *va;
va = sp->getattr(sp, "pos");
pos = va->p;
va = sp->getattr(sp, "ambient");
m.ambient = va != nil? va->p: Pt3(1,1,1,1);
va = sp->getattr(sp, "diffuse");
m.diffuse = va != nil? va->p: sp->v->c;
va = sp->getattr(sp, "specular");
m.specular = va != nil? va->p: Pt3(1,1,1,1);
va = sp->getattr(sp, "shininess");
m.shininess = va != nil? va->n: 1;
/* normal mapping */
va = sp->getattr(sp, "tangent");
if(va == nil)
n = sp->v->n;
else{
/* TODO implement this on the VS instead and apply Gram-Schmidt here */
n = sampletexture(sp->v->mtl->normalmap, sp->v->uv, neartexsampler);
n = normvec3(subpt3(mulpt3(n, 2), Vec3(1,1,1)));
TBN.p = Pt3(0,0,0,1);
TBN.bx = va->p; /* T */
TBN.bz = sp->v->n; /* N */
TBN.by = crossvec3(TBN.bz, TBN.bx); /* B */
n = normvec3(invrframexform3(n, TBN));
}
if(sp->v->mtl != nil && sp->v->mtl->diffusemap != nil && sp->v->uv.w != 0)
m.diffuse = sampletexture(sp->v->mtl->diffusemap, sp->v->uv, tsampler);
if(sp->v->mtl != nil && sp->v->mtl->specularmap != nil && sp->v->uv.w != 0)
m.specular = sampletexture(sp->v->mtl->specularmap, sp->v->uv, tsampler);
lightc = getscenecolor(sp->su->camera->scene, pos, n);
c = Vec3(0,0,0);
for(l = sp->su->camera->scene->lights.next; l != &sp->su->camera->scene->lights; l = l->next){
lightdir = normvec3(subpt3(l->p, pos));
ambient = mulpt3(lightc, Ka);
ambient = modulapt3(ambient, m.diffuse);
Kd = max(0, dotvec3(n, lightdir));
diffuse = mulpt3(lightc, Kd);
diffuse = modulapt3(diffuse, m.diffuse);
lookdir = normvec3(subpt3(sp->su->camera->p, pos));
lightdir = normvec3(addpt3(lookdir, lightdir)); /* half vector */
spec = pow(max(0, dotvec3(lookdir, lightdir)), m.shininess);
specular = mulpt3(lightc, spec*Ks);
specular = modulapt3(specular, m.specular);
c = addpt3(c, addpt3(ambient, addpt3(diffuse, specular)));
}
c.a = m.diffuse.a;
n.w = 1;
sp->toraster(sp, "normals", &n);
specular.a = 1;
sp->toraster(sp, "specular", &specular);
return c;
}
Point3
toonvshader(Shaderparams *sp)
{
Point3 pos, lightdir;
LightSource *l;
double intens;
sp->v->n = model2world(sp->su->entity, sp->v->n);
pos = model2world(sp->su->entity, sp->v->p);
intens = 0;
for(l = sp->su->camera->scene->lights.next; l != &sp->su->camera->scene->lights; l = l->next){
lightdir = normvec3(subpt3(l->p, pos));
intens += max(0, dotvec3(sp->v->n, lightdir));
}
sp->setattr(sp, "intensity", VANumber, &intens);
if(sp->v->mtl != nil)
sp->v->c = sp->v->mtl->diffuse;
return world2clip(sp->su->camera, pos);
}
Color
toonshader(Shaderparams *sp)
{
Vertexattr *va;
double intens;
va = sp->getattr(sp, "intensity");
intens = va->n;
intens = intens > 0.85? 1:
intens > 0.60? 0.80:
intens > 0.45? 0.60:
intens > 0.30? 0.45:
intens > 0.15? 0.30: 0.15;
sp->v->n.w = 1;
sp->toraster(sp, "normals", &sp->v->n);
return Pt3(intens, 0.6*intens, 0, 1);
}
Point3
identvshader(Shaderparams *sp)
{
if(sp->v->mtl != nil)
sp->v->c = sp->v->mtl->diffuse;
return world2clip(sp->su->camera, model2world(sp->su->entity, sp->v->p));
}
Color
identshader(Shaderparams *sp)
{
Color tc;
if(sp->v->mtl != nil && sp->v->mtl->diffusemap != nil && sp->v->uv.w != 0)
tc = sampletexture(sp->v->mtl->diffusemap, sp->v->uv, tsampler);
else
tc = Pt3(1,1,1,1);
sp->v->n.w = 1;
sp->toraster(sp, "normals", &sp->v->n);
return modulapt3(sp->v->c, tc);
}
Point3
ivshader(Shaderparams *sp)
{
sp->v->n = model2world(sp->su->entity, sp->v->n);
sp->v->p = model2world(sp->su->entity, sp->v->p);
return world2clip(sp->su->camera, sp->v->p);
}
Color
triangleshader(Shaderparams *sp)
{
Triangle2 t;
Rectangle bbox;
Point3 bc;
t.p0 = Pt2(240,200,1);
t.p1 = Pt2(400,40,1);
t.p2 = Pt2(240,40,1);
bbox = Rect(
min(min(t.p0.x, t.p1.x), t.p2.x), min(min(t.p0.y, t.p1.y), t.p2.y),
max(max(t.p0.x, t.p1.x), t.p2.x), max(max(t.p0.y, t.p1.y), t.p2.y)
);
if(!ptinrect(sp->p, bbox))
return Vec3(0,0,0);
bc = barycoords(t, Pt2(sp->p.x,sp->p.y,1));
if(bc.x < 0 || bc.y < 0 || bc.z < 0)
return Vec3(0,0,0);
/* wireframe version */
enum { THICKNESS = 8 };
Point2 p01, p12, p20;
double d01, d12, d20, d;
Point2 p, v, r;
p01 = subpt2(t.p1, t.p0);
p12 = subpt2(t.p2, t.p1);
p20 = subpt2(t.p0, t.p2);
p = Pt2(sp->p.x, sp->p.y, 1);
r = subpt2(t.p0, p);
v = Vec2(p01.y, -p01.x);
d01 = fabs(dotvec2(v, r));
r = subpt2(t.p1, p);
v = Vec2(p12.y, -p12.x);
d12 = fabs(dotvec2(v, r));
r = subpt2(t.p2, p);
v = Vec2(p20.y, -p20.x);
d20 = fabs(dotvec2(v, r));
d = min(d01, min(d12, d20));
if(d > THICKNESS)
return Vec3(0,0,0);
return Pt3(bc.x, bc.y, bc.z, 1);
}
Color
circleshader(Shaderparams *sp)
{
Vertexattr *va;
Point2 uv;
double r, d, time;
uv = Pt2(sp->p.x,sp->p.y,1);
uv.x /= Dx(sp->su->fb->r);
uv.y /= Dy(sp->su->fb->r);
va = sp->getuniform(sp, "time");
time = va == nil? 0: va->n;
// r = 0.3;
r = 0.3*fabs(sin(time/1e9));
d = vec2len(subpt2(uv, Vec2(0.5,0.5)));
if(d > r + r*0.05 || d < r - r*0.05)
return Vec3(0,0,0);
return Pt3(uv.x, uv.y, 0, 1);
}
/* some shaping functions from The Book of Shaders, Chapter 5 */
Color
sfshader(Shaderparams *sp)
{
Vertexattr *va;
Point2 uv;
double y, pct, time;
uv = Pt2(sp->p.x,sp->p.y,1);
uv.x /= Dx(sp->su->fb->r);
uv.y /= Dy(sp->su->fb->r);
uv.y = 1 - uv.y; /* make [0 0] the bottom-left corner */
va = sp->getuniform(sp, "time");
time = va == nil? 0: va->n;
// y = step(0.5, uv.x);
// y = pow(uv.x, 5);
// y = sin(uv.x);
y = sin(uv.x*time/1e8)/2.0 + 0.5;
// y = smoothstep(0.1, 0.9, uv.x);
pct = smoothstep(y-0.02, y, uv.y) - smoothstep(y, y+0.02, uv.y);
return Pt3(flerp(y, 0, pct), flerp(y, 1, pct), flerp(y, 0, pct), 1);
}
Color
boxshader(Shaderparams *sp)
{
Point2 uv, p;
Point2 r;
uv = Pt2(sp->p.x,sp->p.y,1);
uv.x /= Dx(sp->su->fb->r);
uv.y /= Dy(sp->su->fb->r);
r = Vec2(0.2,0.4);
p = Pt2(fabs(uv.x - 0.5), fabs(uv.y - 0.5), 1);
p = subpt2(p, r);
p.x = max(p.x, 0);
p.y = max(p.y, 0);
if(vec2len(p) > 0)
return Vec3(0,0,0);
return Pt3(uv.x, uv.y, smoothstep(0,1,uv.x+uv.y), 1);
}
Shadertab shadertab[] = {
{ "triangle", ivshader, triangleshader },
{ "circle", ivshader, circleshader },
{ "box", ivshader, boxshader },
{ "sf", ivshader, sfshader },
{ "toon", toonvshader, toonshader },
{ "ident", identvshader, identshader },
{ "gouraud", gouraudvshader, gouraudshader },
{ "phong", phongvshader, phongshader },
{ "blinn", phongvshader, blinnshader },
};
Shadertab *
getshader(char *name)
{
int i;
for(i = 0; i < nelem(shadertab); i++)
if(strcmp(shadertab[i].name, name) == 0)
return &shadertab[i];
return nil;
}